2016-07-08 12:28 GMT+02:00 Joachim Breitner
Currenlty,
foobar (do f &&& g) x
calls foobar with two arguments, while
(do f &&& g) x
calls (f &&& g) with one argument. The ArgumentDo proposal does not change that, only that the parenthesis become redundant.
I don't think so: https://ghc.haskell.org/trac/ghc/wiki/ArgumentDo#BlockasaLHS explicit states that do f &&& g x parses as (f &&& g) x , so foobar do f &&& g x parses as foobar ((f &&& g) x) under the new proposal, which I find highly confusing. If it doesn't parse like this under the proposal, the wiki page is wrong and/or the proposal is not compositional: Why should being below "foobar" change the parse? "foobar" is not a keyword switching to some different mode.